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Study on the Safety and Effectiveness of Stereotactic Body Radiotherapy with or without Pembrolizumab for Patients with Unresected Stage I or II Non-Small Cell Lung Cancer

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a type of lung cancer known as Non-Small Cell Lung Cancer (NSCLC), specifically in its early stages, Stage I or II, where the cancer cannot be removed by surgery. The study is investigating the effects of a treatment called pembrolizumab, also known by its code name MK-3475, which is a medication given through an intravenous infusion. Pembrolizumab is being tested in combination with a type of precise radiation therapy called Stereotactic Body Radiotherapy (SBRT). The trial will compare the outcomes of patients receiving SBRT with pembrolizumab to those receiving SBRT with a placebo, which is a substance with no active medication.

The purpose of this study is to evaluate the safety and effectiveness of the treatment combinations in patients with unresectable NSCLC. Participants in the study will be randomly assigned to receive either the combination of SBRT and pembrolizumab or SBRT and a placebo. The study will monitor participants over a period to assess how long they remain free from events such as cancer progression or recurrence, which is referred to as Event-Free Survival (EFS). Additionally, the study will look at overall survival rates and other health outcomes related to quality of life and side effects.

Throughout the study, participants will undergo regular health assessments to track their response to the treatment and any side effects they may experience. The trial aims to provide valuable information on whether adding pembrolizumab to SBRT can improve outcomes for patients with early-stage NSCLC who cannot undergo surgery. The study is expected to continue until 2026, with ongoing evaluations to ensure the safety and well-being of all participants.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be informed about the trial's purpose, procedures, and your role as a participant. You will be asked to provide informed consent, which means you agree to participate after understanding all aspects of the study.

  2. Step 2

    Initial assessment

    You will undergo an initial assessment to confirm your eligibility. This includes a review of your medical history, a physical examination, and tests such as a chest computed tomography (CT) scan and a positron emission tomography (PET) scan to confirm the stage of your lung cancer.

  3. Step 3

    Randomization

    If eligible, you will be randomly assigned to one of two groups. One group will receive pembrolizumab along with stereotactic body radiotherapy (SBRT), and the other group will receive a placebo with SBRT. Randomization ensures that each participant has an equal chance of being assigned to either group.

  4. Step 4

    Treatment phase

    If you are in the pembrolizumab group, you will receive pembrolizumab through an intravenous infusion. The dosage is 25 mg/mL, and the frequency and duration will be determined by the study protocol. If you are in the placebo group, you will receive a normal saline solution in the same manner.

    You will also receive stereotactic body radiotherapy (SBRT), a type of radiation therapy that targets the tumor with high precision. The schedule and duration of SBRT will be explained to you by the study team.

  5. Step 5

    Follow-up visits

    Throughout the study, you will have regular follow-up visits. These visits are important to monitor your health, assess the effectiveness of the treatment, and identify any side effects. You will undergo various tests and assessments during these visits.

  6. Step 6

    End of treatment

    At the end of the treatment phase, you will have a final assessment to evaluate your response to the treatment. This will include medical examinations and imaging tests similar to those conducted at the beginning of the study.

  7. Step 7

    Long-term follow-up

    After completing the treatment, you will enter a long-term follow-up phase. This phase involves periodic check-ups to monitor your health and any long-term effects of the treatment. The frequency and duration of these follow-ups will be explained to you by the study team.

Who can join the trial?

8 criteria

  • The patient must have **non-small cell lung cancer (NSCLC)** that has not been treated before. This cancer should be confirmed as **Stage I or II** by specific scans (CT and PET scans). Certain conditions like invasion of the pericardium, more than two nodules, or nodules that are too far apart are not allowed.
  • The patient cannot have thoracic surgery due to other medical conditions, as decided by a team of doctors. Patients who can have surgery but choose a different treatment called **stereotactic body radiotherapy (SBRT)** are also eligible if they clearly document their decision not to have surgery.
  • The patient must have an **ECOG Performance Status** of 0, 1, or 2. This is a scale that measures how well a patient can perform daily activities.
  • The patient must be able to receive **SBRT** and should not have a tumor located in an ultra-central area of the chest.
  • The patient must have adequate organ function within 7 days before starting the study treatment.
  • Female patients must not be pregnant or breastfeeding. They must either not be of childbearing potential or use a highly effective contraceptive method or be abstinent from heterosexual intercourse during the study and for a specified period after the last treatment.
  • Male patients must agree to refrain from donating sperm and either be abstinent from heterosexual intercourse or use contraception during the study and for a specified period after the last treatment, unless they are confirmed to be **azoospermic** (unable to produce sperm).
  • The patient must have a radiation therapy plan that is approved by a central quality assurance vendor.

Who cannot join the trial?

4 criteria

  • Patients with **unresected Stage I or II Non-Small Cell Lung Cancer (NSCLC)** cannot participate. This means the cancer has not been surgically removed.
  • Patients who are not within the specified age range for the study cannot participate.
  • Patients who belong to certain clinical trial groups that are not included in this study cannot participate.
  • Patients who are part of a vulnerable population, which means they might need special protection or care, cannot participate.
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Investigated drugs

  • Pembrolizumab

    is a type of medication known as an immunotherapy. It works by helping your immune system fight cancer cells. In this trial, it is being tested to see if it can improve the treatment of non-small cell lung cancer when used together with a special type of radiation therapy called Stereotactic Body Radiotherapy (SBRT). The goal is to find out if adding Pembrolizumab can help patients live longer without the cancer getting worse.

  • Stereotactic Body Radiotherapy (SBRT)

    is a form of radiation therapy that delivers very precise, high doses of radiation to a tumor. It is used to target cancer cells in the lung while minimizing damage to the surrounding healthy tissue. In this trial, SBRT is being used to treat patients with non-small cell lung cancer, and researchers are studying its effectiveness both alone and in combination with Pembrolizumab.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered as an intravenous infusion, meaning it is given directly into a vein through a needle. It is currently being studied in clinical trials for its effectiveness and safety in treating patients with unresected Stage I or II Non-Small Cell Lung Cancer (NSCLC). The main therapeutic use of Pembrolizumab is to help the immune system fight cancer cells. At the molecular level, it works by blocking a specific protein called PD-1 on immune cells, which helps the immune system recognize and attack cancer cells more effectively. Pembrolizumab is classified as an immune checkpoint inhibitor, a type of drug that helps boost the body's natural defenses against cancer.

Investigated diseases

Non-Small Cell Lung Cancer (NSCLC) – Non-Small Cell Lung Cancer is a type of lung cancer that includes several subtypes such as adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. It typically begins in the tissues of the lungs and is characterized by the uncontrolled growth of abnormal cells. In its early stages, NSCLC may not cause noticeable symptoms, but as it progresses, it can lead to persistent cough, chest pain, and difficulty breathing. The disease can spread to other parts of the body, including the lymph nodes, bones, and brain. The progression of NSCLC is often categorized into stages, with Stage I and II indicating that the cancer is localized and has not spread extensively. As the disease advances, it may become more challenging to manage and can significantly impact a person's quality of life.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-500413-11-00Protocol codeMK3475-867Estimated enrolment586 patientsSponsorMerck Sharp & Dohme LLC

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